Network Service Descriptor support

Network Service Descriptor support

https://blueprints.launchpad.net/tacker/+spec/nsd-support

This proposal describes the plan to add Network Service Descriptor(NSD) support in Tacker. To enable dynamic composition of network services, NFV introduces Network Service Descriptors (NSDs) that specify the network service to be created.

        TOSCA                                NFV

+-----------------------------------+    +----------------+
|         Service Template          |    | Network Service|
| +-------------------+             |    |    Descriptor  |
| | Topology Template |             |    |                |
| |    +---------+    | +----------+|    |    +-----+     |
| |    |  Node   | <--+-| NodeTypes|<----+----| VNFD|     |
| |    | Template|    | +----------+|    |    +-----+     |
| |    +---------+    |             |    |                |
| |    +---------+    | +----------+|    |    +-----+     |
| |    |  Node   | <--+-| NodeTypes|<----+----| VLD |     |
| |    | Template|    | +----------+|    |    +-----+     |
| |    +---------+    |             |    |                |
| |    +---------+    | +----------+|    |    +-------+   |
| |    |  Node   | <--+-| NodeTypes|<----+----| VNFFGD|   |
| |    | Template|    | +----------+|    |    +-------+   |
| |    +---------+    |             |    |                |
| |    +---------+    | +----------+|    |    +-----+     |
| |    |  Node   | <--+-| NodeTypes|<----+----| PNFD|     |
| |    | Template|    | +----------+|    |    +-----+     |
| |    +---------+    |             |    |                |
| +-------------------+             |    |                |
+-----------------------------------+    +----------------+
As shown in above picture, NSD can includes VNFD, VNFFGD, VLD and PNFD.
  • VNFD –> Virtual Network Function Descriptor
  • VNFFGD –> VNF Forwarding Graph
  • VLD –> Virtual Link Descriptor
  • PNFD –> Physical Network Function

In current scope Tacker does not includes PNFD.

Problem description

Tacker builds a generic VNF Manager and a NFV Orchestrator to deploy and operate Virtual Network Functions (VNFs) on an NFV infrastructure platform like OpenStack. But currently needs the ability to describe and orchestrate a collection of VNFs to render a Network Service. It is desired by community to manage and orchestrate network service. NSD template is the way to introduce that capability.

To enable dynamic composition of network services, NFV introduces Network Service Descriptors (NSDs) that describe the network service to be created. NSDs mainly describes the what all network services to be instantiated in the NFVI. An NFV Orchestrator can use NSD to instantiate a network service which may have one or more VNFs, VLs and VNFFGs.

Tacker will provide the support for NSD so that user can orchestrate the collection of VNFs and network services. With NSD support, Tacker will provide a end-to-end TOSCA based network service.

Proposed change

Introduce a new template for network service which contains VNFs, connection points and virtual links.

+---------------------------------+
|   Network Service Descriptor    |
|                                 |
|            +--------+           |
|            |  VNF1  |           |
|            +--------+           |
|                                 |
|            +--------+           |
|            |  VNF2  |           |
|            +--------+           |
|                                 |
|                                 |
|                                 |
|            +--------+           |
|            |  VNFn  |           |
|            +--------+           |
|                                 |
|          +------------+         |
|          | End Point1 |         |
|          +------------+         |
|                                 |
|          +------------+         |
|          | End Point2 |         |
|          +------------+         |
|                                 |
|          +-------------+        |
|          |VirtualLink 1|        |
|          +-------------+        |
|                                 |
|          +-------------+        |
|          |VirtualLink 2|        |
|          +-------------+        |
|                                 |
|                                 |
|          +-------------+        |
|          |VirtualLink m|        |
|          +-------------+        |
|                                 |
+---------------------------------+

Multiple changes will be required, which includes changes to Tacker Client, Horizon, and Server.

+-------------------------------------------+
|     +------------------+                  |
|     |Client Application|                  |
|     +--------+---------+                  |
|              |                            |
|       +------v-----+                      |
|       |  NFVO NS   +----------------+     |
|       |    API     |                |     |
|       +------+-----+             +--v---+ |
|              |                   | VNFM | |
|              |                   +---+--+ |
|              |                       |    |
| +------------v-------------+     +---v-+  |
| |Network Service Descriptor|     | VNF |  |
| +--------------------------+     +-----+  |
+-------------------------------------------+

API changes

New APIs in NFVO plugin will be introduced for NSD and NS.

DB Changes

New tables will be added in database for ‘nsd’ and ‘ns’. Changes in existing ‘vnfd’ will be required which involves substitution_mappings.

Mistral driver Changes

A new mistral driver layer between NFVO plugin and VNFM plugin to translate tosca template into mistral workflow and all mistral APIs to instantiate NS. This intermediate layer will provide a co-ordination between NFVO and Mistral. Like:

  • Generate workflow from TOSCA template.
  • Call Mistral interfaces for NS requests.
  • Wait in PENDING_CREATE state for NS until all VNFs goes to ACTIVE state.
  • Decide to move forward/backward in case of partial failure.

TOSCA Parser Changes

To handle nsd template, TOSCA parser should be configured. TOSCA parser will be updated to handle VNFD, VLD and CP for network service descriptor.

A sample Tosca template for VNFD is below.
Please refer appendix section for complete template.

node_types:
   tosca.nodes.nfv.VNF1:
    requirements:
      - virtualLink1:
        type: tosca.nodes.nfv.VL
        required: true
    capabilities:
      forwarder1:
        type: tosca.capabilities.nfv.Forwarder
topology_template:
  substitution_mappings:
    node_type: tosca.nodes.nfv.VNF1
    requirements:
      virtualLink1: [CP11, virtualLink]
    capabilities:
      forwarder1: [CP11, forwarder]
  node_templates:
    VDU1:
      type: tosca.nodes.nfv.VDU.Tacker
              .
              .
    CP11:
      type: tosca.nodes.nfv.CP.Tacker
              .
              .
    CP12:
      type: tosca.nodes.nfv.CP.Tacker
              .
              .
    VDU2:
      type: tosca.nodes.nfv.VDU.Tacker
              .
              .
    CP13:
      type: tosca.nodes.nfv.CP.Tacker
              .
              .
    VL1:
      type: tosca.nodes.nfv.VL
              .
              .
    VL2:
      type: tosca.nodes.nfv.VL
              .
              .


Proposed sample Tosca template for NSD:

tosca_definitions_version:      tosca_simple_profile_for_nfv_1_0
imports:
    - VNF1
    - VNF2
topology_template:
  VNF1:
    type: tosca.nodes.nfv.VNF1
    requirements:
      - virtualLink1: VL1
  VNF2:
    type: tosca.nodes.nfv.VNF2
  VL1:
    type: tosca.nodes.nfv.VL
    properties:
      network_name: net_mgmt
      vendor: tacker
Regarding above template:
  • ‘CP’ property represents the connection points that will be exposed as part of VNF(mainly to support VNF forwarding graph in future).
  • For each VNF, VIM can be mentioned in properties section, otherwise pick the default one. In current scope, all VNF will be landed on the same VIM, which can be provided in input.

NOTE: The scope of this spec is to handle existing vnfd and defining APIs for NS and support creation of NS without creating the forwarding path.

Data model impact

Data model impact includes the creation of ‘NetworkServiceTemplate’, and ‘NetworkService’ resource model. The schema for these are as:

+--------------------------+
| nsd                      |
+--------------------------+
| id                       |
| name                     |
| type                     |
| description              |
| network_service_template |
| project_id               |
+--------------------------+

+-----------------+
| ns              |
+-----------------+
| id              |
| name            |
| description     |
| nsd_id          |
+-----------------+

There is an impact on existing vnfd resource model. A new field ‘nsd_id’ will be added in vnfd for nsd. In normal VNFD list call, rows corresponding to ‘nsd_id’ will be empty.

REST API impact

NSD will needs to be created to instantiate Network Services. The method of creating NSD follows the TOSCA template scheme we mentioned in the above section.

Example CLI calls:

First create required VNFDs:

tacker vnfd-create vnf1 --vnfd-file samples/nsd/tosca-vnf1.yaml

tacker vnfd-create vnf2 --vnfd-file samples/nsd/tosca-vnf2.yaml

To create NSD:

tacker nsd-create --name NSD1 --nsd-file samples/nsd/tosca-nsd.yaml

To create NS

tacker ns-create --name ns1 --nsd-name NSD1 --vim-name VIM1 --param-file <PARAM-FILE>
--config-file <CONFIG-FILE>

Example param file:

vnfs:
  VNF1:
    vdu-name: VDU1
    cp-name: CP11
nsd:
  virtual-link: VL1

Example config file:

vnfs:
  VNF1:
   ....config

/nsd

+------------------------------------------------------------------------+
|Attribute     |Type   |Access  |Default   |Validation/ |Description     |
|Name          |       |        |Value     |Conversion  |                |
+------------------------------------------------------------------------+
|id            |string |RO, All |generated |N/A         |identity        |
|              |(UUID) |        |          |            |                |
+------------------------------------------------------------------------+
|name          |string |RW, All |None      |string      |human+readable  |
|              |       |        |(required)|            |name            |
+------------------------------------------------------------------------+
|description   |string |RW, All |''        |string      |description of  |
|              |       |        |          |            |NSD             |
+------------------------------------------------------------------------+
|network_servic|dict   |RW, All |None      |template/   |network service |
|e_template    |       |        |          |dict        |template        |
+------------------------------------------------------------------------+
|project_id    |string |RW, All |None      |string      |project id to   |
|              |       |        |(required)|            |launch NSD      |
+------------------------------------------------------------------------+

+--------------------------------------------------------------------------+
|REST Calls  |Type  |Expected  |Request     |Response    |Description      |
|            |      |Response  |Body Schema |Body Schema |                 |
+--------------------------------------------------------------------------+
|create_nsd  |post  |201       |create_req  |create_resp |Creates NSD      |
|            |      |Created   |            |            |                 |
+--------------------------------------------------------------------------+
|delete_nsd  |delete|204 No    |None        |            |Deletes NSD by   |
|            |      |Content   |            |            |name or ID       |
+--------------------------------------------------------------------------+
|show_nsd    |get   |200 OK    |None        |show_resp   |Returns output of|
|            |      |          |            |            |specific NSD ID  |
+--------------------------------------------------------------------------+
|list_nsd    |get   |200 OK    |None        |list_resp   |Returns list of  |
|            |      |          |            |            |NSD Names/IDs    |
+--------------------------------------------------------------------------+

JSON Request and Response Sample:

POST /v1.0/nsds

  • create_req:
{
    "nsd": {
        "name": "NSD_demo",
        "service_types": [
            {
                "service_type": "nsd",
            }
        ],
        "description": "Sample NSD",
        "project_id": "4dd6c1d7b6c94af980ca886495bcfed0",
        "network_service_template": {
            "nsd": "vnf1: template_name:  \r\ndescription: template_description\r\n "vnf2: template_name: OpenWRT \r\ndescription: template_description
        },
    }
}
  • create_resp:
{
    "nsd": {
        "name": "NSD_demo",
        "service_types": [
            {
                "service_type": "nsd",
                "id": "336fe422-9fba-47c7-87fb-d48475c3e0ce"
            }
        ],
        "description": "Sample NSD",
        "project_id": "4dd6c1d7b6c94af980ca886495bcfed0",
        "network_service_template": {
            "nsd": "template_name: OpenWRT \r\ndescription:
            template_description <sample_vnfd_template>"
        },
        "id": "ab10a543-22ee-43af-a441-05a9d32a57da",
    }
}

GET /v1.0/nsds

List nsds - List nsds stored in the catalog.

  • list_res:
{
    "nsds": [
        "nsd": {
            "name": "NSD_demo",
            "service_types": [
                {
                    "service_type": "nsd",
                    "id": "336fe422-9fba-47c7-87fb-d48475c3e0ce"
                }
            ],
            "description": "Sample NSD",
            "project_id": "4dd6c1d7b6c94af980ca886495bcfed0",
            "network_service_template": {
                "nsd": "template_name: OpenWRT \r\ndescription:
                template_description <sample_vnfd_template>"
             },
            "id": "ab10a543-22ee-43af-a441-05a9d32a57da",
        }
   ]
}

GET /v1.0/nsds/{nsd_id}

Show nsd - Show information for a specified nsd id.

  • show_res:
{
    "nsd": {
        "name": "NSD_demo",
        "service_types": [
            {
                "service_type": "nsd",
                "id": "336fe422-9fba-47c7-87fb-d48475c3e0ce"
            }
        ],
        "description": "Sample NSD",
        "project_id": "4dd6c1d7b6c94af980ca886495bcfed0",
        "network_service_template": {
            "nsd": "template_name: OpenWRT \r\ndescription:
            template_description <sample_vnfd_template>"
        },
        "id": "ab10a543-22ee-43af-a441-05a9d32a57da",
    }
}

/ns

+-----------------------------------------------------------------------+
|Attribute   |Type   |Access  |Default   |Validation/ |Description      |
|Name        |       |        |Value     |Conversion  |                 |
+-----------------------------------------------------------------------+
|id          |string |RO, All |generated |N/A         |identity         |
|            |(UUID) |        |          |            |                 |
+-----------------------------------------------------------------------+
|name        |string |RW, All |None      |string      |human+readable   |
|            |       |        |(required)|            |name             |
+-----------------------------------------------------------------------+
|description |string |RW, All |''        |string      |description of   |
|            |       |        |          |            |NSD              |
+-----------------------------------------------------------------------+
|vim_id      |string |RW, All |None      |string      |VIM ID where it  |
|            |       |        |(required)|            |launches         |
+-----------------------------------------------------------------------+
|project_id  |string |RW, All |None      |string      |project id to    |
|            |       |        |(required)|            |launch NSD       |
+-----------------------------------------------------------------------+
|nsd_id      |string |RW, All |None      |string      |NSD id to launch |
|            |       |        |(required)|            |                 |
+-----------------------------------------------------------------------+
|attributes  |dict   |RW, All |None      |dict        |dict containing  |
|            |       |        |(required)|            |config and/or    |
|            |       |        |          |            |param values     |
+-----------------------------------------------------------------------+

+-----------------------------------------------------------------------+
|REST Calls |Type  |Expected  |Body Data |Response   |Description       |
|           |      |Response  |Schema    |Body Schema|                  |
+-----------------------------------------------------------------------+
|create_ns  |post  |202       |schema 1  |           |Creates NSD       |
|           |      |Accepted  |          |           |                  |
+-----------------------------------------------------------------------+
|delete_ns  |delete|202       |None      |           |Deletes NSD by    |
|           |      |Accepted  |          |           |name or ID        |
+-----------------------------------------------------------------------+
|show_ns    |get   |200 OK    |None      |           |Returns output of |
|           |      |          |          |           |specific NSD ID   |
|           |      |          |          |           |                  |
+-----------------------------------------------------------------------+
|list_ns    |get   |200 OK    |None      |           |Returns list of   |
|           |      |          |          |           |NSD Names/IDs     |
+-----------------------------------------------------------------------+

Security impact

Notifications impact

None

Other end user impact

Performance Impact

None

Other deployer impact

Developer impact

Using Mistral workflow for nsd:

Use Mistral workflow for nsd feature. Tacker NFVO will generate Mistral workflow through workflow generator and call to Mistral for generated workflow request. Mistral will create the resources(VNFs, FFG) and respond to NFVO.

+-------------------------------------------+
|     +------------------+                  |
|     |Client Application|                  |
|     +--------+---------+                  |
|              |            +-------------+ |
|        +-----v----+       |  Workflow   | |
|        | NFVO:NSD +------->  Generator  | |
|        +-----+----+       +---------+---+ |
|              |                      |     |
| +------------v-------------+   +----v---+ |
| |Network Service Descriptor|   | Mistral| |
| +--------------------------+   +----+---+ |
|                                     |     |
|                                 +---v--+  |
|                                 | VNFM |  |
|                                 +------+  |
+-------------------------------------------+
Pros:
1: Workflow can already handle multiple cases. 2: In case of failure at any point of time, rollback possible. 3: I think implementation of nsd like feature by using mistral workflow should be easy. 4: After embading mistral with Tacker, any workflow or other already coded such remediation will be in the reach of Tacker.
Cons:
Mistral as third Component:
1: As the Mistral is third components, so:
  • Any changes in mistral may impact the nsd flow.
  • Sometimes in case of compatibility or other issues may be we needs to work with Mistral team.
  • Mistral takes json file in input, so first we needs to create these json data. In case of large number of VNFDs, multiple files will be created. Needs to handle these creation/cleanup. (an investigation in this part required)
  • For an ns call:
    tacker –> Mistral –> tackerClient –> tacker Multiple context switching leads time consuming.
2: An auto-generated workflow can be error prone, should be more
careful while creating mistral workflow to handle corner cases.
3: We have to generate workflow for each resource in nsd
template(i.e . vnfd/vnf) which might be complex in case of large number of vnfs etc.

Implementation

Assignee(s)

Primary assignee:
Dharmendra Kushwaha
Other contributors:
Bharath Thiruveedula <bharath_ves@hotmail.com>

Work Items

  • New APIs in NFVO plugin for NSD and NS
  • NFVO plugin side implementation.
  • Tacker DB configuration for ‘NetworkServiceTemplate’ and ‘NetworkService’.
  • TOSCA parser support for NSD.
  • Mapping of TOSCA node to workflow task.
  • Workflow generator: TOSCA parser will iterate through the each nodes in template and then convert them into tasks.
  • Calls from NFVO-NSD plugin to Mistral to instantiate NS.
  • Logic to wait in PENDING_CREATE state for NS until all VNFs goes to ACTIVE state
  • Logic to take parameters at NS level and pass it onto VNFs
  • Changes for in tacker-horizon and python-tackerclient for NSD.
  • Documentation to explain NSD support feature.
  • Unit test cases
  • Functional test cases

Dependencies

None

Testing

Unit testing

Unit tests will be added for new interfaces. New test cases will be introduced in VNFM for the related extensions.

Functional testing

Functional tests will be added to check the deployed state of all the VNFs.

Documentation Impact

User Documentation

User documentation will describe the NSD features, operations with samples. Python-tackerclient and tacker-horizon side documentation will be added to describe cli/interface details.

Developer documentation

Add developer documentation for the api and usage details

Appendix

TOSCA sample vnf1

tosca_definitions_version: tosca_simple_profile_for_nfv_1_0_0

description: Demo example
  node_types:
  tosca.nodes.nfv.VNF1:
    requirements:
      - virtualLink1:
          type: tosca.nodes.nfv.VL
          required: true
      - virtualLink2:
          type: tosca.nodes.nfv.VL
          required: true
    capabilities:
      forwader1:
          type: tosca.capabilities.nfv.Forwarder
      forwader2:
          type: tosca.capabilities.nfv.Forwarder

topology_template:
  substitution_mappings:
    node_type: tosca.nodes.nfv.VNF1
    requirements:
      virtualLink1: [CP11, virtualLink]
      virtualLink2: [CP14, virtualLink]
    capabilities:
      forwarder1: [CP11, forwarder]
      forwarder2: [CP14, forwarder]

  node_templates:
    VDU1:
      type: tosca.nodes.nfv.VDU.Tacker
      properties:
        image: cirros-0.3.4-x86_64-uec
        flavor: m1.tiny
        availability_zone: nova
        mgmt_driver: noop
        config: |
          param0: key1
          param1: key2

    CP11:
      type: tosca.nodes.nfv.CP.Tacker
      properties:
        management: true
        anti_spoofing_protection: false
      requirements:
        - virtualBinding:
            node: VDU1
        - virtualLink:
            node: VL1

    CP12:
      type: tosca.nodes.nfv.CP.Tacker
      properties:
        anti_spoofing_protection: false
      requirements:
        - virtualLink:
            node: VL2
        - virtualBinding:
            node: VDU1

    VDU2:
      type: tosca.nodes.nfv.VDU.Tacker
      properties:
        image: cirros-0.3.4-x86_64-uec
        flavor: m1.medium
        availability_zone: nova
        mgmt_driver: noop
        config: |
          param0: key1
          param1: key2

    CP13:
      type: tosca.nodes.nfv.CP.Tacker
      properties:
        management: true
      requirements:
        - virtualLink:
            node: VL1
        - virtualBinding:
            node: VDU2

    CP14:
      type: tosca.nodes.nfv.CP.Tacker
      requirements:
        - virtualBinding:
            node: VDU2

    VL1:
      type: tosca.nodes.nfv.VL
      properties:
        network_name: net_mgmt
        vendor: Tacker

    VL2:
      type: tosca.nodes.nfv.VL
      properties:
        network_name: net0
        vendor: Tacker

TOSCA sample vnf2

tosca_definitions_version: tosca_simple_profile_for_nfv_1_0_0

description: Demo example

node_types:
  tosca.nodes.nfv.VNF2:
    capabilities:
      forwarder1:
          type: tosca.capabilities.nfv.Forwarder
topology_template:
  substitution_mappings:
    node_type: tosca.nodes.nfv.VNF2
    capabilities:
      forwarder1: [CP21, forwarder]
  node_templates:
    VDU1:
      type: tosca.nodes.nfv.VDU.Tacker
      properties:
        image: cirros-0.3.4-x86_64-uec
        flavor: m1.tiny
        availability_zone: nova
        mgmt_driver: noop
        config: |
          param0: key1
          param1: key2

    CP21:
      type: tosca.nodes.nfv.CP.Tacker
      properties:
        management: true
        anti_spoofing_protection: false
      requirements:
        - virtualLink:
            node: VL1
        - virtualBinding:
            node: VDU1

    VDU2:
      type: tosca.nodes.nfv.VDU.Tacker
      properties:
        image: cirros-0.3.4-x86_64-uec
        flavor: m1.medium
        availability_zone: nova
        mgmt_driver: noop
        config: |
          param0: key1
          param1: key2

    CP22:
      type: tosca.nodes.nfv.CP.Tacker
      requirements:
        - virtualLink:
            node: VL2
        - virtualBinding:
            node: VDU2

    VL1:
      type: tosca.nodes.nfv.VL
      properties:
        network_name: net_mgmt
        vendor: Tacker

    VL2:
      type: tosca.nodes.nfv.VL
      properties:
        network_name: net0
        vendor: Tacker

TOSCA sample nsd template

tosca_definitions_version: tosca_simple_profile_for_nfv_1_0_0
imports:
    - VNF1
    - VNF2

topology_template:
  node_templates:
      VNF1:
        type: tosca.nodes.nfv.VNF1
        requirements:
          - virtualLink1: VL1

      VNF2:
        type: tosca.nodes.nfv.VNF2

      VL1:
        type: tosca.nodes.nfv.VL
        properties:
          network_name: net_mgmt
          vendor: tacker

TOSCA sample nsd params

vnfs:
  vnf1:
    vdus:
      vdu1:
        param:
          vdu-name: ns-test-vdu11
      vdu2:
        param:
          vdu-name: ns-test-vdu12
      cp11:
        param:
          cp-name: ns-test-cp11
      cp12:
        param:
          cp-name: ns-test-cp12

  vnf2:
    vdus:
      vdu1:
        param:
          vdu-name: ns-test-vdu21
      vdu2:
        param:
          vdu-name: ns-test-vdu22
      cp21:
        param:
          cp-name: ns-test-cp21
      cp22:
        param:
          cp-name: ns-test-cp22
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